Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The DNA isolated from the group A streptococcal bacteriophage SP24 is a linear double-stranded molecule 42.0 kb in length. The DNA has been characterized by electron microscopy, and by agarose gel electrophoresis after cleavage with the restriction endonucleases SalI, BglII, XbaI, PvuI, HindIII, and BamHI. Analysis of SalI digests indicates that two fragments are present in submolar amounts and exist as a subset of sequences present in another SalI fragment. Moreover, overlapping endonuclease fragments suggested that the physical map is circular. This was confirmed when homoduplex phage DNA revealed circular structures with single-stranded tails that were 7.7% of the circumference of the genome length molecule. Tails were observed to be separated by as much as 42% of the circular homoduplex structure. These results indicate that the phage SP24 genome is terminally redundant and circularly permuted; and the data are consistent with a model in which DNA packaging into phage heads is initiated at a specific site on concatermeric DNA and proceeds sequentially to package up to five "headfuls" of DNA per concatemer.
 ...
PMID:A restriction map and analysis of the terminal redundancy in the group a streptococcal bacteriophage SP24. 631 42

When the group A streptococcal bacteriophage SP24 was propagated on an unrelated host strain CS112, it underwent a DNA rearrangement: the rearrangement involved a substitution of unique DNA (2.5 kb) from an unrelated endogenous prophage carried by strain CS112. This substitution event occurred reproducibly upon infection of strain CS112, as DNAs from a number of independent isolates were found to contain similar, but not identical, DNA sequences. Restriction endonuclease mapping suggested that recombination between homologous sequences shared by the infecting phage and the prophage produced the rearrangement. The recombinant phage was shown to adsorb more rapidly to CS112 cells than did wild type SP24 phage particles: It therefore has a selective advantage during multiple rounds of infection.
 ...
PMID:A DNA substitution in the group A streptococcal bacteriophage SP24. 631 43